Mirror columnist Paul Routledge says it's right that children shouldn't be exposed to the risk of asthma and lung disease by parents who smoke behind the wheel

Well, I never! I didn’t think the old fogies had the nerve, but they’ve backed ­children against the baccy barons.

In defiance of the Government, the House of Lords voted decisively to ban smoking in cars carrying children.

This fresh nail in the coffin of the tobacco industry ­coincided with the death of yet another iconic “Marlboro Man” from lung failure. Eric Lawson, the tough guy with the lantern jaw whose tanned, leathery face adorned a million ­billboards, succumbed to chronic obstructive ­pulmonary disease.

He was the poster boy asking the gullible to “Come to Marlboro Country” where the all-American cowboy is king. As long as he smokes Philip Morris fags.

News of the third ­Marlboro Man to die from a smoking-related illness came just before peers debated a Labour proposal to stop adults lighting up in cars with children present.

The verdict was a triumph of common sense over the vested interests of the tobacco industry, traditionally linked to the Tories.

Conservative ministers yesterday abandoned any thoughts of reversing the surprise defeat, offering MPs a free vote on the issue. If, as seems likely, the Commons supports a ban, it will become law. Health Secretary Jeremy Hunt will be responsible for implementing it. The health logic is ­unassailable. Second-hand smoke inside the confines of a vehicle is 20 times stronger – and so infinitely more toxic – than in the open air.

Yet half a million children are exposed to the risk of asthma and lung disease in this way every week by selfish adults who can’t go without a fag no matter how short the journey. Often – most often, I suspect – it is mum and dad who are to blame.

Supporters of the freedom to pollute young lives say only 12% of smokers light up in the car.

I don’t know where they get this figure from, but it still shows a very large level of hazardous exposure.

And I don’t buy the “intrusion of freedom” argument. Sure, it would be a minor curtailment of smokers’ rights. But set against the rights of children to breathe unpolluted air, it is trivial. The further claim that such a ban would be impossible to enforce is invalid. Just because some people choose to break the law is no reason not to have a law, otherwise murder would be lawful.

Britain has successfully outlawed smoking in pubs and clubs, in stations, trains and buses, in ­hospitals and other public places.

A motor car is, arguably, another public space.

This is a moral crossroads for a government whose Tory Public Health Minister Jane Ellison says: “We must do all we can to help children lead healthy lives.”

OK, live up to those high-sounding words. Fail, and Labour promises to legislate if elected.

Another Marlboro Man, William Thourlby, died aged 89 last year. His recipe for a long life? “I never smoked.”